Towards a less stringent groundwater body objective? Feedback from a French heavily industrial and urban study area

Abstract : Groundwater Directive 2006/118/EC (Daughter to Water Framework Directive 2000/60/EC) establishes specific measures in order to prevent and control groundwater pollution. It specifically requires to assess plumes originating from punctual sources such as those due to industrial activities, in order to check if they do not spread and degrade the chemical state of the groundwater bodies. In 2012-2013, BRGM (French Geological Survey) supported by the AERMC (Water Agency on the Mediterranean Rhone River basin) carried out a study to assess the impact of industrial activities on the quality of groundwater bodies in the Rhône river basin. It enables to identify 10 groundwater bodies which were at risk of not reaching the groundwater environmental quality target set by the French application of the Groundwater Framework Directive. Some of these groundwater bodies impacted by persistent and widely spread contaminants such as chlorinated solvents are very unlikely to recover groundwater quality standard by 2027. In this context, AERMC and the BRGM initiated an innovative project in order to define a methodological framework to justify for an exemption of the current groundwater quality objectives and the possibility to propose a less stringent groundwater objective.